It is known that elastic composites can be produced from rubber or plastic particles using suitable binders or adhesives. Polyurethane plastics are preferably used as binders. It is often useful to add pigments and mineral fillers in order to obtain particular properties, for example, for coloring or for influencing hardness and elasticity. Substances of this kind may be added in different ways. Thus, as described in German Offenlegunsschrifts 1,720,059 and 2,156,255 which latter publication corresponds to a combination of U.S. Pat. applications Ser. Nos. 87682 and 88219 filed on Nov. 9, 1970, now U.S. Pat. Nos. 3,801,421 and 3,711,444 respectively, these substances are mixed into the binder, while as described in German Offenlegungsschrift 2 021 682 a powder-form pigment is mixed with the rubber granulate.